Atomic layer deposition (ALD) is used for providing coating layers on substrates for manufacturing products, such as semiconductors, electrical components, optical components or photovoltaic cells. According to the basic characteristics of ALD the coating layers grow on all surfaces of the substrate and cover each surface fully. However, when manufacturing such products it is not always desirable to provide coating layers which cover one surface entirely. For example electrical connections may be provided to the substrates and it is not desirable to form coating layers on the electrical connections. Therefore it is desirable to manufacture substrates for products production in which coating ALD coating layers are formed only on limited sub-areas of a surface of the substrate.
In prior art substrates having only limited sub-areas of a substrate coated with ALD coating layers are formed by two different manners: preventing coating formation of coating layers on the surface of a substrate using masks covering a portion of the surface of the substrate, or removing coating layers from a portion of the surface of the substrate after the coating process. Masks or the like are placed on the surface of the substrate to prevent material growth on the area of the surface of the substrate which the mask covers during the coating process. Produced coating layers are usually removed from the surface of the substrate by etching or the like removal process after the coating layers are produced on the surface of the substrate.
The prior art methods for producing substrates having ALD coating layers only on limited sub-areas of a surface of the substrate require additional process steps to be performed before the actual coating process or after the actual coating process as mentioned above relating to the use of masks and removal of portions of the produced coating layers. These additional process steps lower the production efficiency as they are time consuming and make the production process more complicated. Furthermore, masking does not efficiently prevent coating layers from growing on the masked areas as the precursor gases tend to penetrate from the edge regions of the mask between the mask and the surface of the substrate.